No flow due to pressure buildup in the pump circulation water pipeline
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A circulating water cooling system for a pump was set up on site; 4 kilograms of water were supplied as input water. As soon as the valve in the return pipeline was opened to connect it, no water flowed back. The input water pressure was sufficient, so why couldn’t the water return? Could it be that the return pipeline is blocked, or is the pressure in the return system too high during the startup phase?
There are several possible reasons for this situation: 1. **Clogged return pipe**: It is indeed possible that the return pipe is blocked; check whether there are any foreign objects or deposits blocking the flow of water. 2. **Excessively high pressure in the return water system**: If the pressure in the return water system is higher than that in the supply water system, it will prevent water from flowing. It is necessary to check and adjust the pressure balance in the system. 3. **Valve issues**: Check whether the valves on the return line are fully open. If the valves are not completely open or if there are any faults with them, this can also lead to flow problems. 4. **Pipeline design issues**: Check whether there are any design flaws in the pipelines, such as excessively long return pipelines or too many bends, which may increase water flow resistance. It is recommended to conduct inspections and make adjustments in these areas to resolve the issue. .
This post was last edited by CHANGBAISHI on 2024-8-19 06:23. At the beginning of water supply, the outlet valve should be slightly opened while ensuring the pressure at the pump outlet, in order to pressurize the system; once pressurized, everything will be under control automatically. As for the water flow rate, it can be determined by listening to the sound of the water when the outlet valve is slightly opened to supply water to the system. Additionally, it is necessary to check whether the installation location of the flow meter and its installation requirements are met. Oh, the opening degree of the check valve should be set such that the system pressure remains at or above the pressure at the pump outlet; it cannot be opened fully. For reference.
In a closed-loop piping circulation system, during operation, it is necessary to open the high-point vent valve to fill the system with liquid; after the vent valve has continuously discharged the liquid, it should be reduced in size or closed. If air forms in the circulatory system, it will cause obstruction and prevent circulation. Open the inlet valve of the circulation pump, close the outlet valve, start the circulation pump, and use the outlet valve to control whether the outlet pressure and flow rate of the pump meet the requirements for circulation. It is necessary to further confirm whether the circulation system pathway is unobstructed, and whether there are any blockages in valves or pipes.
"In terms of operation, it is necessary to open the high-point vent valve to fill the system with liquid; after the vent valve has continuously discharged the liquid, it should be reduced in size or closed. \"If air forms in the circulation system and causes a blockage, circulation cannot take place\" – does this mean evacuating the circulation pipeline first and then filling it completely with liquid?
Sometimes the inlet pressure is low, failing to meet the requirements for complete filling; in such cases, a circulation pump must be used to fill the system. During the first filling of the system, it is essential to ensure that liquid is continuously discharged from the high-point vent.
It’s most likely that the pipe is blocked, or there’s some valve that hasn’t been fully opened